Lateral-flow or immunochromatographic test kits and methods for the detection of the presence or concentration of chemical residues or analytes or classes thereof from liquid samples have been developed. An example of one such test kit includes a pregnancy test kit.
Particularly in the food safety area it has long been recognized that residue detection should be accurate, inexpensive and easily conducted. Consumers and governments are becoming increasingly aware of the necessity for testing foods for the presence of undesirable residues naturally occurring or otherwise.
Since a large portion of the consumers are children, food safety has long been critical in the dairy industry. Antibiotic residues used on a dairy farm occasionally appear in the milk supply. The hazards associated with these undesirable residues, include allergic reactions, assisting the propagation of new and sometimes drug resistant microorganisms and other long term health risks.
Government agencies have established in some cases legal limits for particular residues in foods, for example antibiotic residues in milk. Residues above the "legal" limit are considered unsafe for human consumption. Residue levels below the legal limit are considered "safe". It is important, therefore, that detection methods, in addition to being inexpensive and easily conducted, do not give positive results when residues are below legal limits so that otherwise acceptable milk, or other foods, are not discarded or otherwise treated as containing residues above legal limits.